Unitary plastic laminate

ABSTRACT

Plastic laminates are prepared using decor layers containing 1025% of particulate polyacrylonitrile resin, the polyacrylonitrile resin being incorporated in the decor during its manufacture on a paper machine. The laminates meet NEMA specifications even though less resin is used and fewer process steps are required.

United States Patent 11 1 1111 3,887,743 Lane June 3, 1975 UNITARYPLASTIC LAMINATE 2,777,232 Slgg; Mallisoni 260/8073 3,220, 1 l1 1 Petrouos 161/413 [751' Invent Lane, Chllhcothe, 3,547,769 1/1970 Albri k et61.... 161/413 3,734,807 5/1973 Kelly et al 161/5 [73] Asslgnee' ggCorporatlm" Dayton 3,736,220 5/1973 Shah 161/413 1 Filedi 1 1972 PrimaryExaminer-Mayer Weinblatt 21 A L N 305 170 Assistant Examiner-Edith L.Rollins 1 pp 0 ,1 Attorney, Agent, or FirmEarl B. Brookbank, Jr.

[52] US. Cl. 428/206; 428/327; 4422880553)? [57] ABSTRACT [51] 1111. C1B44f 1/00 Plastic laminates are Prepared using decor layers [58] Field61 Search 161/5 413,248,263; taining 10-25% of particulatepolyacrylonitrile resin, 26028075; 162/164 the polyacrylonitrile resinbeing incorporated in the decor during its manufacture on a papermachine. The [56] References Cited laminates meet NEMA specificationseven though less f UNITED STATES PATENTS resin is used and fewer processsteps are required.

2,658,828 10/1953 Pattilloch 162/164 5 Claims, 2 Drawing Figures OVERLAY65-75% AMINOPLAST RESIN ECOR 10-25 POLYACRYLONITRILE RESIN CORE STOCK30% P HE NOLIC RESIN OVERLAY 65-75% AMINOPLAST RESIN ECOR 10-25POLYACRYLONITRILE RESIN CORE STOCK 30% PHENOLIC RESIN MANUFACTURE DECORON PAPERMACHINE ADDING PARTICULATE POLYACRYLONITRILE RESIN TO PULP "'lPRINT WITH PATTERN I (optional) I CORESTOCK ASSEMBLE LAMINATE OVERLAY(CONVENTIONAL) OVERLAY, DECOR 8x CORESTOCK (CONVENTIONAL) CURE 8CONSOLIDATE UNDER HEAT 8: PRESSURE FINISHED LAMINATE UNITARY PLASTICLAMINATE BACKGROUND OF THE INVENTION 1. Field of the Invention The fieldof the present invention is that of plastic laminates wherein a core orbase is covered with a resin-containing decorative surface layer, termeddecor, which in turn is covered with a resin impregnated wear layercalled an overlay. The core may comprise multiple layers of resinimpregnated paper. The finished plastic laminate is a unitary structuresuitable for use as table and counter tops, wall panels and the like.Generally, this invention is concerned with a novel decor, method ofproducing a laminate therefrom, and to the laminate so produced. 2.Description of the Prior Art Presently, plastic laminates of the typeherein considered are generally prepared by (l) assembling a number ofcore paper sheets which have been saturated with about 30% ofphenolaldehyde condensation polymer in B stage; (2) covering the coresheets with an opaque decorated paper, called a decor, containing from30 to 42% of an aminoplast such as a melamineformaldehyde resin; and (3)applying over the decor an overlay paper containing from 65 to 75% of amelamine aldehyde resin. The assembly of core sheets, decor and overlayis then subjected to heat and pressure to consolidate them into aunitary structure, and to complete the cure of the resins therein to aninsoluble, infusible state.

, According to the prior art, core stock, decor and overlay papers aremanufactured according to conventional papermaking methods. If desired,decor sheets are first printed with a design or pattern but in any eventare passed through a machine called a treater in which the decor paperis saturated with aminoplast resin. Similar processing on a treater isrequired to incorporate the desired kind and amount of resin into thecore stock and overlay papers.

Such prior art laminates have been known for a long time, and over theyears, there have been various improvements in resins used, in themanufacture of the decor paper to add post forming properties to thelaminates, and a variety of overlay papers have been produced toincrease the wear resistance of the finished laminates.

On the other hand, the necessary process steps have shown little or nochange, and in total, there has been little reduction, if any, in thecost of such laminates.

SUMMARY OF THE INVENTION According to the present invention, laminatesare produced with elimination of one of the prior art process steps andwith a significant reduction in the amount of resin used in producingthe finished laminate.

As shown in FIG. 2, this is accomplished by incorporating from to 25% ofparticulate polyacrylonitrile resin in the decor at the time the decoris manufactured on the papermachine, the amount of particulate resinused being a function of the basis weight of the decor, as will beexplained later herein. This decor may then be printed, if desired, withno loss in print quality and converted to a laminate without furtheraddition of resin to the decor. Conventional core stock and overlays areused.

It is indeed unexpected that a 65 lb./3000 sq. ft. decor for example,having only about one-half the amount of resin (20% of polyacrylonitrilecompared to 30-42% melamineformaldehyde of the prior art) can be madeinto a laminate which meets all the NEMA specifications for Type A andType C laminates. Even more surprising is the discovery that a 37.5|b./3000 sq. ft. decor containing only 10% by weight of particulatepolyacrylonitrile, when made into a laminate with conventional corestock and overlay, will meet the same NEMA specifications. Substantialeconomy is achieved in producing the laminates of this invention byeliminating the step of impregnating the decor sheet with resin on atreater, and by reason of the substantial reduction in the amount ofresin incorporated in the decor.

DESCRIPTION OF THE DRAWINGS FIG. 1 is an enlarged diagrammatic sectionalelevation of a typical laminate of this invention; and

FIG. 2 is a flow-sheet showing the method of producing the laminate ofFIG. I. 7

DETAILED DESCRIPTION The laminates of the present invention utilize corestock and overlays which are conventional in the art. The decor used inthe laminate is produced on a conventional papermachine with addition ofa particulate polyacrylonitrile resin to yield a resin content of 10 to25%, depending in part on the basic weight of the decor. This decor maybe incorporated into a laminate without further addition of resin, usingcore stock and overlay of the prior art. By contrast, prior art decorsare most often impregnated in a separate operation with 30 to 42% of amelamine-aldehyde resin.

A suitable polyacrylonitrile resin is of the type disclosed in US. Pat.No. 2,777,832 and preferably is a copolymer of 95% acrylonitrile and 5%methylacrylate with a uniform average molecular weight of between about60,000 and 90,000. As produced according to US Pat. No. 2,777,832, theresin is in the form of extremely compact rounded discrete particlesranging in size from 10 to 50 microns diameter. The resin particles maybe added to decor paper pulp and filler slurries without further sizereduction, even though the size range of 10 to 50 microns is usuallyconsidered coarse in terms of conventional papermaking. Using ungroundresin particles of 10 to 50 micron size range will result in a roughpaper surface with attendant reduction in printing quality unlessincreased pressing and calendering are used.

If desired, the polyacrylonitrile resin particles may be reduced to asmaller particle size range, such as by wet grinding in slurry form. Theground slurry may then be mixed with the other decor paper furnishcomponents to yield the desired 10 to 25% of the polymer, by weight,based on the total weight of the decor paper.

As used herein, the polyacrylonitrile resins are polymers containing atleast by weight of acrylonitrile units. These include copolymers,including binary and ternary polymers containing at least 85% by weightof acrylonitrile in the polymer molecule, or a blend comprisingpolyacrylonitrile and copolymers comprising acrylonitrile with from 2 to50% of another polymeric material, the blend having an overallpolymerized acrylonitrile content of at least 85% by weight.

For example, the polymer may be a copolymer of from 85 to 98%acrylonitrile and from 2 to 15% of another monomer containing the C=Clinkage and copolymerizable with acrylonitrile. Suitable monoolefinicmonomers, include acrylic, alpha-chloroacrylic and methacrylic acids;the acrylates, such as methylmethacrylate, ethylmethacrylate,butylmethacrylate, methoxymethyl methacrylate, beta-chloroethylmethacrylate, and the corresponding esters of acrylic and alphachloroacrylic acids; vinyl chloride, vinyl fluoride, vinyl bromide, vinylidenechloride, l-chloro 1 bromo-ethylene; methacrylonitrile; acrylamide andmethacrylamide; alphachloroacrylamide; or monoalkyl substitutionproducts thereof, methylvinyl ketone; vinyl carboxylates, such as vinylacetate, vinyl chloroacetate, vinyl propionate, and vinyl stearate;N-vinylimides, such as N-vinylphthalimide and N-vinylsuccinimide,methylene malonic esters, itaconic acid and itaconic esters;N-vinylcarbazole, vinyl furane; alkyl vinyl esters; vinyl sulfonic acid;ethylene alpha, betadicarboxylic acids or their anhydrides orderivatives, such as diethylcitraconate, diethylmesacnate, styrene,vinyl naphthalene; vinyl-substituted tertiary heterocyclic amines, suchas the vinylpyridines and alkylsubstituted vinylpyridines, for example,2 vinylpyridine, 4-vinylpyridine, 2-methy1-5- vinylpyridine, etc.;l-vinylimidazole and alkylsubstituted l-vinylimidazoles, such as 2-, 4-,or 5- methyl-l-vinylimidazole, and other C=C containing polymerizablematerials.

In the papermaking operation, the polyacrylonitrile particles behave asan inert mineral filler, and are retained in the decor paper web toabout the same degree as mineral fillers such as titanium dioxide.Typically, retention of both the resin particles and titanium dioxidewill range from 86 to 90%.

Because the decor paper of this invention is not rewetted in asubsequent resin impregnating step, greater latitude in paper-makingoperations is possible.

For example, it is not necessary to incorporate wet strength propertiesinto the decor, and pressing and calendering of the paper to a highdegree is possible without regard to porosity and/or resin impregnatingproperties. Refining or beating of the pulp can be carried to a lowerfreeness, if desired, without concern for a non-existent subsequentimpregnating operation. Thus printing characteristics of the decor canbe improved by adjustment of papermaking variables in a manner whichwould normally adversely affect resin impregnating properties.

After printing, if desired, the decor so produced is ready to laminate.A sheet thereof is placed over the desired number of core stock sheetsand an overlay placed over the decor, as shown in FIG. 1. This assemblyis placed in a press and pressed at about 1000 to 1500 lb. per sq. in.and a temperature of from 270F. to 297F. for about 20 minutes.Generally, heating and pressing cycles required for curing and bondingprior art decor, core stock and overlays are satisfactory for use withthe decor of this invention. Time, temperature and pressure requirementsare those imposed by the phenolic and aminoplast resins in the assembly,which are more than adequate to achieve the flow and consolidation ofthe particles of polyacrylonitrile resin present in the decors of thisinvention. The resultant laminate is a unitary structure which issuitable for use in table and counter tops or the like.

The product and process of the invention will be further illustrated bythe following examples:

EXAMPLE I Ready-to-laminate decor papers were prepared from a furnish of50.6% bleached wood pulp 30.0% titanium dioxide 19.4% polyacrylonitrileresin powder The wood pulp was dispersed in water first, followed byaddition of the titanium dioxide which was thoroughly mixed with thewood pulp over a period of about 15 minutes. The polyacrylonitrile resinwas then added as a water suspension of solid particles of the resinwhich had previously been ground to a particle size ranging from 1 to 3microns. Alum was then added to give a pH of 4.5, followed by additionof ammonia to yield a pH of 6.5.

Next, the pulp, filler and resin slurry was refined to 450 ml CanadianStandard Freeness, diluted, and delivered to the head box of afourdrinier papermachine. Basis weight was adjusted to about 65 lb. per3000 sq. ft.

Operation of the machine was normal with no problems evident from theaddition of the polyacrylonitrile resin powder. During the run, refiningwas increased to reduce freeness to 385 ml C.S.F., and wet pressing andcalendering were increased to produce a Sheffield smoothness (felt ortop side) of about 105, compared to a value of about 125 on the firstpart of the run. Near the end of the run, sodium bicarbonate buffersolution was added to the wet formed web on the wire section of thepapermachine to adjust press cure time when later pressed intolaminates. A retention aid and a minor amount of wet strength resin wereadded continuously during the machine run. It was found that broke orwaste from the machine, produced during the run, could be repulped andrecycled, up to a level of without adverse effects. The four separatedecors produced had the following properties:

A B C D Basis Wt., lb. (24 36500) 65,1 64.8 64.2 64.5 Caliper, mils 4.94.8 4.6 4.7 Tensile, M.D., gm/in 7100 8040 8280 7220 Wet Tensile, M.D.,gm/in i200 1220 600 650 Ash, 7! 26.5 26.0 25.1 24.] Smoothness (Top)Shefiield 122 N4 98 Machine Speed, f.p.m. 250 303 303 303 Freeness,C.S.F. 450 385 350 350 Sodium bicarbonate, lh./br. 28.4 32.6 Broke, 7120.0 90

1 YPQC I Spec.

- A B C D (NEMA) Overlay resin /z 74 65 74 65 74 65 74 ResistancetoBoiling Water OK OK OK OK OK OK OK OK (NEMA 1.01-2.03 Resistance toHeat OK OK OK OK OK OK OK OK (NEMA LD1-2.02)

Resistance to Cigarette burn, sec. 107 136 110 129 121 12 4 H8 75 (NEMALD1-2.()4) Postforming, b" R. OK OK OK OK OK OK OK /4" OK (NEMA LDl-2.ll) lmpact Resistance 40" 40" 38" 38" 38" 40 34" 24" (NEMA LDl-2.l5)Dimensional Stabi1ity*M.D. 0.77r l.1 (NEMA LD1-2.08) C.D. 0.37z l.4

*Gross Dimensional Change. 71

An examination of the data shows that the laminates of the inventionmeet all NEMA Specifications for Type C post forming laminates.

EXAMPLE 1] lb/3000 sq. ft. of unbleached kraft core stock containing31.5 to 32.9% B stage phenolic resin, one sheet of decor and'l sheet ofoverlay containing 65.2% of melamine aldehyde resin'. The pressing wascarried out at 1400 psi for 67 minutes; Of this 67 minutes approximately20 minutes were at a temperature in excess of 275F. with a peaktemperature of 292F.

Tests on the finished laminates showed the following, using NEMAstandard test methods except for the blister test and craze resistancetest.

An examination of the data shows that, except for caliper, all NEMAspecifications for Type A general purpose laminates are fully met orexceeded. Anadditional sheet of core stock would correct this, and inany event, it is unrelated to laminate properties associated with thekind and amount of resin in the decor layer.

Of particular significance are the resistance to heat, cigarette burnresistance and the blister test, all of which are surprising results,since the decor used has only one-half the conventional amount of resin,yet internal bonding of the decor after pressing is fully up tospecifications.

NEMA

Spec. Type Decor used A A C C A Finish Smooth Textured Smooth TexturedCaliper, mils 54 56 56 54 62fi Resistance to boiling 11 0 OK OK OK OK OKResistance to heat OK OK OK OK OK Resistance to cigarette burn. sec. 111113 121 126 110 Impact resistance +40" +40 +40 36" Dimensional stability(Gross chang'e)C.D. 0.35 0.34 0.43 0.33 0.9 Blister Test*, sec..

above 350F. 20 14 18 17 10) Craze Resistance**,

cycles 8 OK 10 6 OK 10 (6 min.) Color Fastness to light. hrs. 48 48 4848 48 (NEMA LD1-2.06) Color vChange None None None None S1. OK SurfaceChange None None None None None Resistance to boiling water (NEMALD1-2.07)

Wt. inc.. 7! 7.1 5.8 5.0 6.1 10% Thickness lnc., 71 4.7 3.6 3.7 4.9 107rWater Swell (NEMA Wt. Inc., 7! 11.3 10.2 8.5 9.6

Thickness lnc.. '71 9.3 9.1 7.5 8.6

Values in 'j are not NEMA Specifications Blister test: Time in secondsto produce a blister after heating to a surface temperature of 350F..using a radiant heater and fixed geometry.

Craze resistance: Expressed as the number ofcyclcs of a) 2-hour exposureto steam at atmospheric pressure and (h) drying and examination. Resultsare reported as the number of cycles to produce slight Grazing of thesurface.

7 EXAMPLE III TO VI These Examples show results obtained with differentamounts of polyacrylonitrile resin particles of two dif- 8 plications, arelatively low basis weight decor is acceptable. The high opacity andhigher basis weight needed to mask the dark colored core stock toproduce bright whites is no longer a factor for these darker colors.

These Examples show the laminate properties obtained ferent particlesize ranges. After producing the decor when using varying amounts ofpolyacrylonitrile resin P pe of the Various mp hey were made mto in adecor of 52 lb./3000 sq. ft. basis weight. pressed laminates accordingto the method'and construction set and sheets of creped kraft comparedforth in Example I. Tests on the finished laminates Papermachine runswere made generally following Showed the followlngi the procedures ofExample I, using varying amounts of Example No. 111 IV V VI Basis Wt.,lb./3000 sq. ft. 65 65 65 65 Bleached wood pulp 50 50 45 53 Titaniumdioxide 30 3O 3O 32 Polyacrylonitrile resin 27# 20 Polyacrylonitrileresin l-3p. 2O 25 Cigarette resistance, sec. 100 l 17 l 16 1 13 Impactresistance +40 +40" +40" +40" Heat resistance OK OK OK OK Blister test17 I3 15 2 hr. Water Boil-Wt. Inc. 7a 4.0 3.7 3.2 3.9 Thickness Inc. 7:0 2.0 2.0 4.0 Craze, No. of cycles V. S1. 7 8 6 Slight 8 6 Crazed 8 9 98 Gross Dimensional Change MD. 7: 0.22 0.53 0.20 0.22 CD. 0.65 0.97 0.550.51 Water Swell-l 8 hrs. 70, Wt.Inc. 7.0 6.1 5.5 6.2 Thickness Inc.14.2 7.7 8.0 12.0

The particulate polyacrylonitrile resin used in Examples III to VI wasobtained by wet grinding of a slurry of resin particles having aninitial size ranging from 10 to 50 microns, by passage through anattrition mill. Prior to grinding the particles are compact andessentially spherical in shape. The action of the attrition mill chopsthe spheres into smaller, randomly shaped particles in a range of sizes.The 2-7 micron size was obtained by one pass through the mill, while twopasses yielded a size range of 1-3 microns.

Examination of the data shows that, within narrow limits, all ExamplesIII to V1 resulted in acceptable laminates. Note that swelling after 18hours in 70F. water showed greater thickness increases for Examples 111and VI, indicating that water was penetrating into the laminatestructure to a higher degree than for Examples IV and V. While this testuses a NEMA standard method, there is no specification related to it foreither Class A or Class C laminates. These examples indicate that resincontent in the range of 15 to had little effect on laminate properties,while the two difi'erent particle sizes show little or no difference inlaminate properties.

EXAMPLES VII TO IX For many decorative uses, relatively dark colors andpatterns such as wood grains are desired. For these ap- ExampleResistance to heat Additionally, for Type C (postforming) laminates, the

bottom two sheets of core stock were replaced with 2 phenolicimpregnated creped kraft paper layers. Pressing conditions for the TypeC laminates were 1000 psi pressure for 34 minutes as compared to 1400psi for 40 minutes for Type A, with temperature the same for both. Thefollowing results were obtained:

Example VII VIII IX Furnish 71 by weight Softwood pulp 325 CSF Hardwoodpulp 325 CSF Titanium Dioxide Polyaerylonitrile resin (l-Su) StarchDecor Properties Basis Weight-lb./3000 sq. ft. Caliper, mils smoothness,Sheffield, felt Type A Laminate Tests Resistance to boiling water OK OKOK OK OK OK VII VIII IX Impact resistance, in. Res. to cigarette burn,sec. Blister test,* see. over 313F Resistance to boiling water, 2 hr.

% Weight increase Thickness increase Type C Laminate Tests Cigaretteburn, sec. Blister test,* see. over 313F Postforming radius 8 radius 8 88 radius Postformed test specimens were rated on a subjective scale of 1to 8, with 8 representing a bend of the indicated radius showing nocrazing or other adverse effects and 1 represents a complete failure.Generally speaking, a rating of 7 is acceptable for most applications,while 6 shows objectionable crazing in the area of the bend.

Examination of the data reveals that, at 52'to 53.5

EXAMPLES X TO XII Examples VII to IX were repeated, except that thebasis weight of the decor was adjusted to 37 to 38 1b./3000 sq. ft.,with the following results:

Example X X1 The results using 37 to 38 lb./3000 sq. ft. decor, withpolyacrylonitrile resin content ranging from 10 to 20%, are in goodagreement with those obtained with 52 to 53.5 1b./3000 sq. ft. (seeExamples VI] to IX).

Other samples of the ready-to-laminate decors of Examples VII to XIIwere printed prior to preparing Type A laminates therefrom. Generally,it was observed that the lower basis weight decors at the lowerpolyacrylonitrile contents showed somewhat smoother surfaces andsomewhat better printing quality. However, all were judged to becommercially acceptable.

EXAMPLES X111 TO xv The decor papers of these examples were preparedaccording to the method of Example I, using by weight ofpolyacrylonitrile resin particles in each case. In Example XIII, theresin particles were unground (size range 10 to microns diameter); inExample XIV the resin particles were ground for 1 hour in an at- 20trition mill, and in Example XV they were ground for 8 hours in anattrition mill.

The resulting decor papers were made into NEMA Type A and Type Claminates according to the procedures of Examples VII to IX, and thelaminates then tested. The following results were obtained:

XII

Polyacrylonitrile resin( 15;L), 7: 20 14 10 Decor Properties Basis wt.,1b./3000 sq. ft. 37.0 38.0 37.5 Caliper. mils 3.94 3.72 3.48 smoothness,Sheffield, sec. 200 153 128 Type A Laminate Tests Resistance to boilingwater OK OK OK Resistance to heat OK OK OK Impact resistance, in. +40+40 +40 Resistance to cigarette burn. sec. 145 133 130 Blister test,sec. over 313F. 45.7 44.9 47.2 Resistance to boiling water, 2 hr.

Wt. increase, '71 7.4 7.8 7.2 Thickness increase, 71 7.2 9.4 8.4 Type CLaminate Tests Cigarette burn, sec. 1 17 1 19 Blister test, see. over313F. 55.0 54.7 51.8 Postforming radius 8 8 8 16" radius 8 8 8 A" radius4 6 5 Example XIII XIV XV Furnish Bleached wood pulp, 76 76 76 Titaniumdioxide, 4 4 4 Polyacrylonitrile resin (10 to 50p.) 20 Polyacrylonitrileresin (2 to 10p.) 20 Polyacrylonitrile resin (1 to 3p) 20 Paper TestsBasis Wt, 1b./3000 sq. ft. 65.5 66.5 64.0 Caliper, mils 6.9 6.7 6.2Porosity, sec. for 400 ml. 33.2 46.0 82.8 Smoothness, Sheffield 220 220180 Type A Laminate Tests Cigarette burn, sec. 148 Blister test, see.over 313F. 51.0 51.0 51.2 Resistance to boiling water OK OK OKResistance to heat OK OK OK Impact resistance, in. +40 +40 +40Resistance to boiling water,

2 hr. Wt. 1nc., 7.7 7.1 7.0 Thickness Inc., '7: 10.1 8.1 8.1 Type CLaminate Tests Cigarette burn, sec. 135 133 l 14 Blister test, see. over313F 43.0 59.0 51.0 Impact resistance, in. +40 +40 +40 Postforming. 5%"radius 8 8 8 radius 8 8- 8 /4" radius 6+ 6 6+ The Sheffield smoothnesstest (where the lower numbers are the smoother surfaces) reflects theeffect of resin particle size, the finest particles giving the smoothestpaper surfaces.

Caliper or thickness of the papers shows the coarse resin-t yield thethickest paper, with progressive decrease to the finest resin particlepaper.

Porosity tests on the paperalso show the coarse resin to give a moreporous sheet and a progressive decrease to the finest resin particlepaper.

These effects of resin particle size on paper properties are those to beexpected. These differences largely disappear after the decor papers areincorporated into laminates, all of them yielding both Type A and Type Claminates which meet the appropriate NEMA specifications.

Test printing of the decor papers of these examples showed print qualityto improve as resin particle size decreased. These papers were producedunder identical papermachine pressing and calendering conditions, andthe observed printing quality differences are those to be expected.

In the following Examples, the improvement in printing quality resultingfrom different degrees of calendering was investigated.

EXAMPLES XVI TO XX In these examples a decor paper containing 50%bleached wood pulp, 30% titanium dioxide filler and 20% of particulatepolyacrylonitrile resin of a to 50 micron particle size was subjected todifferent calendering conditions, and the resultant papers, printed andmade into Type A laminates. The procedures of Example l were followed,except that the entire furnish of pulp, filler and resin was beatentogether in a beater for minutes and then given one pass through ajordan prior to the papermaking operation. The following test resultswere obtained;

XVIII While emphasis in the foregoing has been on meeting NEMAspecifications for Type A General Purpose and Type C Post Forminglaminates, it should be self evident that all the decor papers ofExamples I-XX meet the less stringent specifications for NEMA Type BVertical Surface laminates.

What is claimed is:

l. A unitary plastic laminate consisting essentially of acoreimpregnated with a phenolic resin, a decor sheet and an overlayimpregnated with an aminoplast, said decor sheet having from 10 to 25%by weight of particulate polyacrylonitrile resin uniformly dispersedtherein during manufacture thereof, said polyacrylonitrile resin being acopolymer of 85 to. 98% by weight of acrylonitrile and 15 to 2% byweight of an ethylenically unsaturated monomer copolymerizabletherewith, said polyacrylonitrile having a molecular weight ranging from60,000 to 90,000.

2. The laminate of claim 1 wherein said polyacrylonitrile resin has aparticle diameter ranging from 1 to microns.

3. The laminate of claim 1 wherein said decor sheet carries a printedpattern.

4. A decor paper adapted for incorporation as a decorative layer in aplastic laminate together with a core impregnated with a phenolic resinand an overlay impregnated with an aminoplast, said decor papercontaining from I0 to 25% by weight of particulate polyacrylonitrileresin uniformly dispersed therein during manufacture thereof, saidpolyacrylonitrile resin being a copolymer of 85 to 98% by weight ofacrylonitrile and 15 to 2% by weight of an ethylenically unsaturatedmonomer copolymerizable therewith, said polyacrylonitrile having amolecular weight ranging from 60,000 to 90,000.

Example XVI XVII XIX XX ML No. of passes through nip 0 I 3 l 3 Nippressure, Ib/lin. in. 300 300 850 850 Pa er Pro erties Basis WL,lb./3000 sq. ft. 62 62 62 62 62 Caliper, mils 6.3 5.0 4.6 4.9 4.5Porosity, sec. for 400 ml. 61.2 220 272 278 329 Smoothness. Sheffield265 177 159 168 165 K & N Ink receptivity 29.3 34.8 38.4 35.3 38.8 InkSensitivity. 71 33.1 39.6 43.3 39.7 44.4 Laminate Tests (Type A) Blistertest, see. over 313F. 55.0 60.0 61.8 58.0 58.6 Cigarette burn 132 133130 130 136 Resistance to heat OK OK OK OK OK Impact resistance +40 +40+40 +40 +40 Resistance to boiling water-2 Hr.

Wt. increase, 7: 7.0 6.7 6.1 6.2 6.2

Thickness inc., 7.2 9.1 6.0 8.2 7.1 Print Quality 5 3 2 4 1 Notes:

K & N Ink smeared on paper for 30 sec., wiped off and reflectancemeasured with a Bausch and Lamb Opacimeter using white body.

Ratio of reflectance of inked area to uninked area of paper. "Arbitraryscale of I-best. S-poorest.

5. The decor paper of claim 4 wherein said polyacrylonitrile resin has aparticle diameter ranging from I to 50 microns.

1. A UNITARY PLASTIC LAMINATE CONSISTING ESSENTIALLY OF A COREIMPREGNATED WITH A PHENOLIC RESIN, A DECOR SHEET AND AN OVERLAYERIMPREGNATED WITH AN AMINOPLAST, SAID DECOR SHEET HAVING FROM 10 TO 25%BY WEIGHT OF PARTICULATE POLYACRYLONITRILE RESIN UNIFORMLY DISPERSEDTHEREIN DURING MANUFACTURE THEREOF, SAID POLYACRYLONITRILE RESIN BEING ACOPOLYMER OF 85 TO 98% BY WEIGHT OF ACRYLONITRILE AND 15 TO 2% BY WEIGHTOF AN ETHYLENICALLY UNSATURATED MONOMER COPOLYMERIZABLE THEREWITH, SAIDPOLYACRYLONITRITE HAVING A MOLECULAR WEIGHT RANGING FROM 60,000 TO90,000.
 1. A unitary plastic laminate consisting essentially of a coreimpregnated with a phenolic resin, a decor sheet and an overlayimpregnated with an aminoplast, said decor sheet having from 10 to 25%by weight of particulate polyacrylonitrile resin uniformly dispersedtherein during manufacture thereof, said polyacrylonitrile resin being acopolymer of 85 to 98% by weight of acrylonitrile and 15 to 2% by weightof an ethylenically unsaturated monomer copolymerizable therewith, saidpolyacrylonitrile having a molecular weight ranging from 60,000 to90,000.
 2. The laminate of claim 1 wherein said polyacrylonitrile resinhas a particle diameter ranging from 1 to 50 microns.
 3. The laminate ofclaim 1 wherein said decor sheet carries a printed pattern.
 4. A decorpaper adapted for incorporation as a decorative layer in a plasticlaminate together with a core impregnated with a phenolic resin and anoverlay impregnated with an aminoplast, said decor paper containing from10 to 25% by weight of particulate polyacrylonitrile resin uniformlydispersed therein during manufacture thereof, said polyacrylonitrileresin being a copolymer of 85 to 98% by weight of acrylonitrile and 15to 2% by weight of an ethylenically unsaturated monomer copolymerizabletherewith, said polyacrylonitrile having a molecular weight ranging from60,000 to 90,000.